1. Field of the Invention
This invention relates to an electromagnetically driven shutter for a camera which has the blades thereof driven by an electromagnetic force.
2. Description of the Prior Art
The conventional shutter mechanism for a camera comprises a shutter blade part having a light shielding property, a driving part consisting of a shutter blade driving spring or the like, a control part for controlling the shutter time and a winding part for setting each of these parts into a predetermined state.
Meanwhile, the advancement of applications of electronics to cameras has prompted arrangement to lessen the number of parts required and, as seen in the so-called electronic shutter, the shutter time control part has come to be changed from a mechanical shutter time control mechanism to an electromagnetic shutter time control mechanism. However, the shutter blade part, the driving part and the winding part in general have remained unchanged from their mechanical arrangement. In the conventional electronic shutter, therefore, the complexity of these mechanical parts has been causing a high cost, frequent troubles and other disadvantages. Besides, these mechanical parts have necessitated a mechanical interlocking arrangement with other mechanisms and thus design work on a camera has been greatly restricted because of the mechanical interlocking arrangement required.
To solve this problem, there has recently been proposed and put to a practical use an improvement on the shutter mechanism wherein the shutter blades are directly and electromagnetically driven to obviate the necessity of the shutter blade winding part and the driving part is arranged to serve also as control part to permit simplification of the structural arrangement of the shutter mechanism, reduction in the number of required parts, reduction in cost and allowing a greater degree of latitude for design work.
Generally, the shutter blade part of such an electromagnetically driven shutter bounce upon completion of its travel. To prevent such a bounce, it is first conceivable to use a friction brake or an antibounce claw as seen in the conventional spring driven shutter. However, these conventional antibounce members not only require delicate adjustment work but also are inferior in durability and cause a high cost of manufacture. In addition to such disadvantages, they necessitate the use of a complex interlocking mechanism for bringing these operating member back to their initial positions.